Machine pistol having hydraulic breech locking and obturation



MACHINE PISTOL HAVING HYDRAULIC BREECH' LOCKING AND OBTURATION Filed Jan. 27, 1966 .Au .-22,19s7 c. L. WILSON 3,336,838

INVENTOR C'Zzrzzk J. Wilson United States Patent .0

3,336,838 MACHINE PISTOL HAVING HYDRAULIC BREECH LOCKING AND OBTURATION Curtis L. Wilson, 3103 Elizabeth, Space 25, Pueblo, Colo. 81003 Filed Jan. 27, 1966, Ser. No. 523,474 2 Claims. (Cl.'89-197) ABSTRACT OF THE DISCLOSURE A machine pistol having a spring loaded, divided bolt locked and obturated by hydraulic pressure. The bolt sections have enlarged mating heads with bores therethrough which align when one of the bolt sections is rotated to relieve hydraulic pressure and permit manual retraction of the bolt sections.

This invention relates to a machine pistol and more particularly to an automatic firearm employing hydraulic breech locking and obturation.

Briefly, the invention consists of a spring loaded divided bolt normally locked and obturated in a closed,

firing position by pressure of hydraulic fluid in a chamber in the receiver body of the weapon. The fluid further acts as a recoil buffer. The bolts have enlarged mating heads having bores therethrough. By rotating one of the bolt sections, the bores are aligned to relieve hydraulic pressure thereon whereby the bolt may be easily retracted by hand. i 7

It is a primary object of this invention to provide an automatic firearm in which the bolt mechanism is locked and obturated by hydraulic pressure.

It is another object to provide means in the bolt mechanism whereby the bolt may be retracted easily by hand.

A further object is to provide means for adjusting the hydraulic pressure in the hydraulic fluid chamber so as to automatically relieve the hydraulic pressure upon recoil of the bolt.

A still further object is to provide an automatic weapon that does not depend upon mechanical lugs to obturate the breech mechanism thereby eliminating wear and necessary replacement of the bolt mechanism.

These and other objects and advantages of the present invention will be fully apparent from the following description when taken in connection with the annexed drawing, in which:

FIG. 1 is a somewhat schematic axial section view of the weapon of the invention showing the bolt mechanism in locked position;

FIG. 2 is a similar view showing the bolt mechanism in full recoiled position; I

FIG. 3 is a cross sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a perspective view of the forward bolt section; .and,

FIG. 5 is a perspective view of the rearward bolt section.

With reference to'the drawing in detail, wherein like reference numerals indicate like parts throughout the several views, numeral 1 indicates generally the pistol of theinvention.

As shown in FIGS. 1 and 2, only the operating elements essential for illustrating the invention are shown. Such elements or mechanisms as the stock, firing means, trigger, ejecting means are not shown since they constitute no part of this invention, the invention being in the bolt mechanism per se.

The pistol 1 includes a receiver body 2 and a barrel 3 which is attached to body 2 by threads 4. Barrel 3 is pro- 3,336,838 Patented Aug. 22, 1967 vided with a bore 5, and a firing chamber 6 at its breech end.

Receiver body 2 is provided with a central bore 7 which extends completely therethrough. A counterbore 8 is provided substantially midway of bore 7 and forms a chamber 9 for hydraulic fluid. A second smaller counterbore 10 is provided as shown for a purpose to be described later.

A threaded plug 11 is provided to close the rearward end of bore 7.

An opening 12 in the forward end of body 2 receives a conventional magazine 13 which contains rounds 14. One round is shown in FIG. 1 in the firing chamber 6.

The bolt mechanism comprises a forward bolt section 15 and a rearward bolt section 16. Forward bolt section 15 carries the cartridge case ejector and the firing pin. both not shown. Bolt 15 is provided at its rearward end with an enlarged head 17 which is perforated with longitudinally spaced relief bores 18.

Bolt 16 is also provided with an enlarged head 19 and similar bores 20*.

Bolts 15 and 16 slide in bore 7 and heads 17 and 19 slide in counterbore 10. Bolt 16 may be prevented against rotation as by a key 21 which rides in a keyway 22.

Bores 18 and 20 are circumferentially spaced in heads 17 and 19 respectively and will register when the head 17 is rotated one eighth of a turn. Eight bores are shown in each head. More or less can be provided as expedient for the eflicient operation of the bolts.

' A bolt spring 23 in chamber 9 and encircling bolt section 16 normally urges bolt section 16 forwardly to closed position for firing.

Means for rotating bolt section 15 to align bores 18 with bores 19 for easy retraction of the bolt sections manually are provided and may consist of a handle 24 attached to bolt section 15 and extending through the ejecton slot 25.

Means for relieving the hydraulic pressure in body 2 to permit full recoil of the bolt sections are provided and comprise a bore 27 extending for a length therein and a port 28 extending between bore 27 and chamber 9 as shown. A threaded pressure plug 29 is threadably mounted in the rearward end of bore 27 and a plunger 30, normally urged forwardly in bore 27 by a spring 31 complete the assembly.

A plug 32 of compressible material, such as soft rubber, is mounted in central bore 7 between the rearward end of bolt section 1 6 and closure plug 11 to form a seal therebetween.

' Operation The pistol 1 is shown in its position for firing in FIG. 1 and bores 18 and 20 in heads 17 and 19 are in oflset relation.

Chamber 9 is filled with a hydraulic fluid and some of the fluid will flow through bores 20 in head 16 to form a seal between the abutting faces of bolt sections 15 and 16 and between the periphery of heads 17 and 19 and counterbore 10 to obturate the bolt bores thus providing a positive lock-up for a predetermined amount of hydraulic fluid pressure against heads 17 and 19.

This lock-up is possible due to the step or reduction in wall dimensions due to counterbore 10 into which heads 17 and 19 fit.

It will be obvious that unless the hydraulic pressure of fluid in chamber 9 is relieved, bolt heads 17 and 19 cannot move rearwardly and into chamber 9, or unless bores 18 and 20 are aligned to permit fluid therethrough.

In firing position, the heads 17 and 19 are seated in counterbore 10, and bores 18 and 20 are not aligned.

Rearward thrust on the forward face of forward bolt 15 caused by firing of a round in firing chamber causes some of the hydraulic fluid in chamber 9 to be forced through port 28 and against piston 30 which is biased forwardly by the spring 31 which has a preset load value. No fluid can be forced into this area against the springload pressure applied to piston 30 until the fluid pressure exceeds in p.s.i. the pressure preset against spring 31 and piston 30 by adjusting plug 29.

Plug 32 provides a buffer for bolt 16 when the weapon is fired.

As the bolt section 15 retracts, the empty cartridge shell of round 14 in firing chamber 6 is removed by the ejecting mechanism, not shown, and is ejected through the ejection slot 25.

Piston 30 returns to its forward position in bore 27 when the fluid enters counterbore 10, since the pressure has been relieved in chamber 9. Spring 23 returns the bolt sections forward to its firing position and also the bolt section 15 strips another round 14 from magazine clip 13 and rams it into firing chamber 6.

After firing of the first round, the firing of the other rounds will be automatic for as long as the trigger (not shown) is pulled.

When the pistol 1 is exhausted of ammunition it will be necessary to move the bolt sections to retracted position by hand to reload.

Handle 24 is rotated in a counterclockwise manner to align bores 18 with bores 20 in heads 17 and 19 to permit the heads to be moved easily through the hydraulic fluid since as the bolt sections 15 and 16 are retracted by handle 24, the fluid flows through bores 18 and 20 in heads 17 and 19 to the forward side of the heads.

Bolt spring 23 forces bolt sections 15 and 16 closed for firing the initial round.

Hence, it is obvious that the bolt sections 15 and 16 are held in locked position by the hydraulic fluid while firing the round 14 in firing chamber 6 and are obturated fully thereby.

While only a preferred form of the invention has been shown and described, other forms of the invention are contemplated and numerous changes and modifications may be made therein without departing from the spirit of the invention as set forth in the appended claims.

What is claimed is:

1. A machine pistol comprising in combination, a receiver body, a barrel having a firing chamber at its breech end and being attached to said receiver body, there being an axial bore through said receiver body and in axial alignment with said barrel, said axial bore being counterbored to define a chamber and a counterbore having a smaller diameter than said chamber, said chamber adapted to be filled with a hydraulic fluid, means housed in said receiver body for relieving the fluid pressure in said chamber, a spring loaded forward bolt section slidable in said axial bore in said receiver body, a rearward bolt section slidable in said axial bore, an enlarged head integral with each bolt section and arranged in abutting relation, there being a series of circumferential, longitudinally arranged bores through each head and the bores in the forward head being in offset relation with the bores in the rearward head during automatic operation of said pistol, both of said heads being slidable in said counterbore, said bolt sections being obturated and locked by the hydraulic fluid when in firing position, the fluid pressure in said chamber being automatically relieved by said means upon recoil of said bolt sections whereby they are permitted to be fully recoiled, and means attached to said forward bolt section for rotating said forward bolt section to align said bores in said heads whereby said bolt sections may be retracted manually.

2. A machine pistol as set forth in claim 1 wherein said means for retracting saidbolt sections manually comprises a handle detaehably secured to the forward bolt section and extending through the ejection slot of said pistol.

References Cited UNITED STATES PATENTS 2,497,350 2/1950 Ferda 89-198 2,632,391 3/1953 Kintzinger 89194 X FOREIGN PATENTS 339,486 6/ 1921 Germany.

BENJAMIN A. BORCHELT, Primary-Examiner.

SAMUEL FEINBERG, Examiner.

S. C. BENTLEY, Assistant Examiner. 

1. A MACHINE PISTOL COMPRISING IN COMBINATIJON, A RECEIVER BODY, A BARREL HAVING A FIRING CHAMBER AT ITS BREECH END AND BEING ATTACHED TO SAID RECEIVER BODY, THERE BEING AND AXIAL BORE THROUGH SAID RECEIVER BODY AND IN AXIAL ALIGNMENT WITH SAID BARREL, SAID AXIAL BORE BEING COUNTERBORED TO DEFINE A CHAMBER AND A COUNTERBORE HAVING A SMALLER DIAMETER THAN SAID CHAMBER, SAID CHAMBER ADAPTED TO BE FILLED WITH A HYDRAULIC FLUID, MEANS HOUSED IN SAID RECEIVER BODY FOR RELIEVING THE FLUID PRESSURE IN SAID CHAMBER, A SPRING LOADED FORWARD BOLT SECTION SLIDABLE IN SAID AXIAL BORE IN SAID RECEIVER BODY, A REARWARD BOLT SECTION SLIDABLE IN SAID AXIAL BORE, AN ENLARGED HEAD INTEGRAL WITH EACH BOLT SECTION AND ARRANGED IN ABUTTING RELATION, THERE BEING A SERIES OF CIRCUMFERENTIAL LONGITUDINALLY ARRANGED BORES THROUGH EACH HEAD AND THE BORES IN THE FORWARD HEAD BEING IN OFFSET RELATION WITH THE BORES IN THE REARWARD HEAD DURING AUTOMATIC OPERATION OF SAID PISTOL, BOTH OF SAID HEADS BEING SLIDABLE IN SAID COUNTERBORE, SAID BOLT SECTIONS BEING OBTURATED AND LOCKED BY THE HYDRAULIC FLUID WHEN IN FIRING POSITION, THE FLUID PRESSURE IN SAID CHAMBER BEING AUTOMATICALLY RELIEVED BY SAID MEANS UPON RECOIL OF SAID BOLT SECTIONS WHEREBY THEY ARE PERMITTED TO BE FULLY RECOILED, AND MEANS ATTACHED TO SAID FORWARD BOLT SECTION FOR ROTATING SAID FORWARD BOLT SECTION TO ALIGN SAID BORES IN SAID HEADS WHEREBY SAID BOLT SECTIONS MAY BE RETRACTED MANUALLY 